code: def test_features_extractor_no_features(self):
      model_spec = config_pb2.ModelSpec()
      eval_config = config_pb2.EvalConfig(model_specs=[model_spec])
      feature_extractor = features_extractor.FeaturesExtractor(
          eval_config
      )
      tfx_io = tf_example_record.TFExampleBeamRecord(
          raw_record_column_name=constants.ARROW_INPUT_COLUMN,
          physical_format="inmem",
          telemetry_descriptors=["testing"],
      )
  
      with beam.Pipeline() as pipeline:
          result = (
              pipeline
              | "Create" >> beam.Create([b""] * 3)
              | "DecodeToRecordBatch" >> tfx_io.BeamSource(batch_size=3)
              | "InputsToExtracts"
              >> model_eval_lib.BatchedInputsToExtracts()
              | feature_extractor.stage_name
              >> feature_extractor.ptransform
          )
  
          def check_result(got):
              self.assertLen(got, 1)
              self.assertIn(constants.FEATURES_KEY, got[0])
              self.assertEmpty(got[0][constants.FEATURES_KEY])
              self.assertIn(constants.INPUT_KEY, got[0])
              self.assertLen(got[0][constants.INPUT_KEY], 3)
  
          util.assert_that(result, check_result, label="CheckResult")
  
file_path: model-analysis/tensorflow_model_analysis/extractors/features_extractor_test.py
imports: from absl.testing import parameterized
  import apache_beam
  from apache_beam.testing import util
  import numpy
  import tensorflow
  from tensorflow_model_analysis import constants
  from tensorflow_model_analysis.api import model_eval_lib
  from tensorflow_model_analysis.eval_saved_model import testutil
  from tensorflow_model_analysis.extractors import features_extractor
  from tensorflow_model_analysis.proto import config_pb2
  from tfx_bsl.tfxio import tf_example_record
  from google.protobuf import text_format
  from tensorflow_metadata.proto.v0 import schema_pb2
label_desc: Use image node_id 1 for calling the FeaturesExtractorTest obj's underlying member method code with example usage: obj.test_features_extractor_no_features() without return types